Synchrotron light characterization of free metal and oxide nanoparticles

This work presents a pioneering experimental approach to the study of the interaction of free transition metal nano-sized systems with synchrotron radiation. The results of experiments performed on titanium and titanium oxide nanoparticles (clusters) are presented. The choice for these systems was mainly motivated by their strategic character from the point of view of nanostructured materials assembling, as Ti-based nanostructured materials are widely used in several application fields. The details of the developed experimental set-up and conceptual tools are described. The designed experimental set-up enables independent probing of morphology, reactivity and decay dynamics of excited states of the free nanoparticles, and this results to be mandatory for the emerging complexity of the system under study. Characterization of the nanoparticles is presented in the central part of the work. The chemical reactivity to molecular species of free Ti and TiOx nanoparticles is discussed. The reported morphology, structure and decay dynamics of nanoparticles demonstrate the need for a new picture for their description, alternative to the compact spherical shape model usually adopted for cluster spectroscopy experimental results, and nearer to concepts which are more familiar to the aerosol community. The presented results open interesting perspectives in the view of filling the gap between applications of nanostructured materials and their fundamental understanding.